Commercial aircraft utilize a variety of passenger seating configurations and designs. Historically, aircraft passenger seats have been manufactured using heavy and bulky materials that satisfy certain structural design requirements and passenger comfort requirements. Such components can contribute a significant amount to the overall weight of an aircraft, particularly when the aircraft includes seats for hundreds of passengers. Weight reduction is becoming increasingly important in modern aircraft design. A reduction in the weight of the aircraft structure may allow the aircraft to carry more fuel, thus extending the flight range. A reduction in the weight of the aircraft structure may also allow the aircraft to carry additional passengers or cargo, thus increasing the potential profitability of the aircraft.
The amount of legroom and personal space in a commercial aircraft influences the overall comfort of the passenger. In practice, the bulky materials and thick padding utilized in conventional aircraft passenger seats consume precious cabin space that could otherwise be used for increased legroom or used for additional rows of seats. Such bulky materials are usually necessary for structural support and thick padding is often necessary to provide sufficient cushioning for the seated passengers.
Since modern commercial aircraft design places extreme importance on the benefits of lightweight components, design constraints are often placed upon other desirable features such as comfort and convenience. This is particularly apparent in aircraft seat design because the aircraft is typically configured with hundreds of such seats and customer comfort is of paramount concern. Conventional economy class seat cushion designs have relied almost completely on foamed rubber cushioning schemes which suffer from a variety of shortcomings, including compromises made between durability and comfort. In the seating scheme of a typical airplane, the thickness and density of the foams used in the cushion and backrest are carefully balanced between passenger comfort and the overall weight of the seat cushion.
Aircraft passenger seat cushion design can be improved in a variety ways depending upon which of several benefits are featured. One such improved design featuring substantial weight reduction in a composite assembly is disclosed in copending U.S. application Ser. No. 11/383,867, filed May 17, 2006 which is incorporated herein by reference.
Further improvements are possible in accordance with the present seat cushion design and these improvements can be readily incorporated in the aforementioned composite seat design, as well as other conventional seat designs. With the subject seat cushion design, even an economy class seat can be enhanced in terms of safety, comfort and weight. The present improved design also offers additional design choices to aircraft purchasers by improving this important aspect of seating design.
These improvements are achieved, in part, by utilizing a crushable, energy-absorbent element not heretofore utilized in a seat cushion assembly. This crushable element serves to improve passenger safety and maneuverability in hard landing scenarios. The energy-absorbent, crushable, enhanced maneuverability component is combined with the seat cushion assembly and serves to reduce the forces that may be transferred from a seat structure to the spine, pelvis and femur of the passenger, thereby enhancing the passenger's ability to rapidly exit the aircraft in some emergency situations.
It will be appreciated that the subject improved cushion design also achieves weight reduction, enhanced comfort and an improved margin of safety through its unique combination of cushioning and crushable elements.
Prior conventional seat design approaches, particularly for economy seating, attempted to improve seating cushions by combining different foam densities and types to specific regions of the cushion. The desire to relieve pressure and discomfort related to long term sitting is achieved by judicious selection of foam materials, but this alone is insufficient to enhance safety and maneuverability in a hard landing situation.
Varying the variety and quantity of foam cushioning materials can yield improvements in comfort, but this will not necessarily furnish a meaningful or substantial weight savings. Furthermore, the reliance on foam as the sole supporting element of a relatively comfortable seat cushion generally means such foam will lack sufficient durability required for long in-service life and will offer little or no safety and maneuverability improvements.
Aircraft cushions heretofore have not had a specific component designed to crush under very specific and tightly controlled load conditions, thereby enhancing safety and maneuverability of passengers by absorbing sudden energy spikes and permanently crushing a portion of the seat cushion under emergency situations. This crushing mechanism minimizes the transfer of large energy spikes to the legs, pelvis and spine of a seated passenger, greatly enhancing the ability for rapid emergency egress.
Thus, the new cushion design maintains and improves current comfort levels and meets all anthropometric seating requirements while reducing the overall weight of the seating system and improving safety.
Accordingly, it is desirable to provide an improved passenger seat cushion for aircraft applications. In addition, it is desirable to have a passenger seat cushion design having an improved combination of comfort and safety features. Other desirable features and characteristics of embodiments of the present invention will become apparent from the following descriptions and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.